Research supported in part by U.S. Public Health Service grant MH-16080.

Comments on the delayed treatment design are offered as an amendment to the Heath et al. discussion by pointing out two important assumptions of their recommended design, and tracing through implications of those assumptions for the interpretation of treatment effects. (Author/PN)

A general analysis strategy is proposed such that the universe of inference is increased incrementally. The strategy prevents logically incongruent findings that occasionally result when the conventional analysis strategy is employed. (Author)

Studies designed to assess the efficacy of interventions with organically impaired infants in terms of how well the experimental designs used controlled for threats to interval validity were analyzed. The use of methodologically more rigorous designs in evaluation studies is recommended to prevent or ameliorate the adverse effects of…

A weighted harmonic means analysis is presented that incorporates all of the available data, preserves the planned proportionality of the design, and avoids the problems associated with the replacement of missing data with sample estimates. (Author/BW)

A concise table is presented based on a general measure of magnitude of effect which allows direct determinations of statistical power over a practical range of values and alpha levels. The table also facilitates the setting of the research sample size needed to provide a given degree of power. (Author/CM)

A solution to some problems of maximized contrasts for analysis of variance situations when the cell sizes are unequal is offered. It is demonstrated that a contrast is maximized relative to the analysis used to compute the sum of squares between groups. Interpreting a maximum contrast is discussed. (Author/GK)

A design for evaluation studies of educational programs should provide valid and defensible inferences. Goals of evaluation are the identity of major components of inferences and specific validity concerns. Design problems may be resolved by creatively utilizing features of specific evaluations in designing unique conditions that permit valid…

The impact of a legal reform on child abuse reporting in the District of Columbia is evaluated. Results suggest that reporting legislation may be useful in reform efforts by extending the requirements to new groups and precipitating efforts to implement legal requirements of those already required to report. (Author/GK)

This article builds on an earlier discussion of the importance of the Type II error (beta) and power to the hypothesis testing process (CE 511 484), and illustrates the methods by which sample size calculations should be employed so as to improve the research process. (Author/CT)

The authors use examples to illustrate how the design of a study conveys the overall strategy and soundness of the investigation. Elements of research design that are discussed include setting, subjects, sample, treatment, measurement, and communication of results. (CT)

Discusses the purpose of research on library issues and problems and the use of the scientific method in a library context. Four research methodologies are described as well as measurement scales and research techniques. (BK)

Describes the design, execution, and reporting of a fictitious library research project conducted by a children's librarian in the future. Problems in gaining support, in designing the study, and in presenting the results effectively are highlighted, and possible solutions are presented. (BK)

The recently developed log-linear model technique for the analysis of contingency tables has many potential applications within educational research. This paper describes the two major models, log-linear and logit-linear, that are employed under this approach. (Author/JKS)

Describes an index for the evaluation of a media product. A pretest measure of an aspect of the product is taken, the audience is exposed to the product, a posttest measure is taken, and the index is computed as a ratio of the difference scores to the total change possible. (MER)